PROPOSED REPLACEMENT BRIDGE AXE LAKE ROAD · 2018. 12. 19. · PROPOSED BRIDGE REPLACEMENT AXE LAKE...

FINAL VERSION

D.M. WILLS ASSOCIATES LTD.

PROPOSED REPLACEMENT BRIDGE ‐ AXE LAKE ROAD

GEOTECHNICAL INVESTIGATION

Proposed Replacement Bridge

Axe Lake Road

Township of McMurrich‐Monteith, Ontario

P‐0016727‐0‐00‐100‐01

December 2018

PROPOSED BRIDGE REPLACEMENT AXE LAKE ROAD

TOWNSHIP OF MCMURRICH-MONTEITH DECEMBER 2018, FINAL REPORT

2-120 Progress Court, North Bay (Ontario) Canada P1A 0C2 – T 705.476.2550 F 705.476.8882

Our Ref.: P-0016727-0-00-100-01

Prepared by:

J. R. Berghamer, P.Eng. Service Director



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Revision and Publication Register

Revision N° Date Modification and/or Publication Details

0 August 29, 2018 Preliminary Report Issued

1 December 6, 2018 Final Report Issued

Distribution

1 pdf Mr. David Bonsall, P. Eng.

D.M. Wills Associates Ltd.

150 Jameson Drive

Peterborough, ON

K9J 0B9

Property and Confidentiality

“This report can only be used for the purposes stated therein. Any use of the report must take into consideration the object and scope of the mandate by virtue of which the report was prepared, as well as the limitations and conditions specified therein and the state of scientific knowledge at the time the report was prepared. Englobe Corp. provides no warranty and makes no representations other than those expressly contained in the report.

This document is the work product of Englobe Corp. Any reproduction, distribution or adaptation, partial or total, is strictly forbidden without the prior written authorization of Englobe and its Client. For greater certainty, use of any and all extracts from the report is strictly forbidden without the written authorization of Englobe and its Client, given that the report must be read and considered in its entirety.

No information contained in this report can be used by any third party without the prior written authorization of Englobe and its Client. Englobe Corp. disclaims any responsibility or liability for any unauthorized reproduction, distribution, adaptation or use of the report.

If tests have been carried out, the results of these tests are valid only for the sample described in this report.

Englobe’s subcontractors who have carried out on-site or laboratory work are duly assessed according to the purchase procedure of our quality system. For further information, please contact your project manager.”

Formatting changes may have occurred during conversion to PDF version. The content however, remains the same.



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Table of Contents

1 INTRODUCTION ................................................................................................... 1

1.1 Site Conditions ...................................................................................................... 1

2 FIELDWORK ......................................................................................................... 1

3 SUBSURFACE CONDITIONS .............................................................................. 2

3.1 Subsurface Summary Description ......................................................................... 2 3.1.1 Proposed Structure .................................................................................................. 2

3.2 Groundwater Data ................................................................................................. 4 3.2.1 Area of Proposed Structure ...................................................................................... 4

4 DISCUSSION AND RECOMMENDATIONS ......................................................... 5

4.1 Frost Protection ..................................................................................................... 5

4.2 Foundation Recommendations ............................................................................. 5 4.2.1 Scour Considerations ............................................................................................... 6

4.2.2 Shallow Foundation Recommendations .................................................................. 7

4.2.3 Deep Foundation Recommendations ...................................................................... 8 4.2.3.1 End Bearing Piles ...................................................................................... 8 4.2.3.2 Helical Piles ............................................................................................... 9

4.2.4 Lateral Earth Pressure ............................................................................................. 9

4.2.5 Earthquake Parameters ......................................................................................... 10

4.3 Excavation, Dewatering, and Backfill .................................................................. 10

5 LIMITATIONS ..................................................................................................... 12

Tables

Table 1 Borehole Refusal .................................................................................................... 4

Table 2 Groundwater Levels at Structure Location ............................................................. 4

Appendices

Appendix 1 Drawings

Appendix 2 Subsurface Data

Appendix 3 Lab Data

Appendix 4 Photo Essay



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1 Introduction

As requested by the Client, D.M. Wills Associates Ltd., Englobe Corp. (Englobe) has carried out the geotechnical investigation for the proposed Axe Lake Road Bridge Replacement in the Township of McMurrich-Monteith, Ontario (see Key Plan, Drawing No. 1, Appendix 1). For the purposes of this investigation, Axe Lake Road is considered to be locally oriented in an east-west direction. We have completed the field and laboratory testing programs and submit the factual results in this report along with our comments and recommendations.

It is understood that it is proposed to replace the existing Axe Lake Road River Bridge located on Axe Lake Road near Sprucedale, Ontario. Work at the site includes removal of the existing bridge structure including timber crib abutments and replacement with modular steel girder bridge on new foundation.

The purpose of the geotechnical investigation was to ascertain the subsurface and groundwater conditions at the location of the proposed bridge to provide geotechnical recommendations for the design of the structure foundations and construction operations.

1.1 Site Conditions

The single lane bridge is a steel girder structure supported on timber cribs at the abutments. The bridge has a timber deck. Axe Lake Road is a gravel surface road. See Photo Essay Appendix 4.

There are no reported underground services in the area of the bridge.

2 Fieldwork

The fieldwork for this geotechnical investigation was carried out on August 23, 2018. The fieldwork consisted of two (2) sampled boreholes (Boreholes (BH) Nos. 1 and 2).

The locations of the boreholes are shown on the Borehole Location Plan, Drawing No. 2 in Appendix 1.

The boreholes were advanced with a track mounted CME-45B drill rig equipped with continuous flight hollow stem augers and standard augers. The field work was under the full time direction of an experienced member of our engineering field staff who was responsible for underground service locates, logging individual borings, retrieving samples, field sample classification, plus overall field/drill supervision. At select boreholes, samples were obtained at frequent intervals of depth by using the Standard Penetration Test (SPT) method. The SPT method of sampling involves advancing a 50 mm outside diameter split spoon sampler with the force of a 63.5 kg hammer, freely dropping 760 mm, mounted in a trip (automatic) hammer. The number of blows per 300 mm penetration is recorded as the “N” value. A Dynamic Cone Penetration Test was undertaken at the boreholes to provide a measure of a material's in-situ resistance to penetration and the depth of refusal. When cohesive deposits

PROPOSED BRIDGE REPLACEMENT AXE LAKE ROAD TOWNSHIP OF MCMURRICH-MONTEITH DECEMBER 2018, FINAL REPORT

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were encountered, the in-situ strength was measured using a MTO size field vane, vane collar, and calibrated torque meter. All samples taken during this investigation were stored in labeled airtight containers for transport to our North Bay laboratory for visual examination and select laboratory testing. The routine laboratory testing consisted of natural moisture content determination and particle size analysis on select samples. Samples remaining following testing will be stored for a period of three months following the date of this report and then discarded unless otherwise instructed.

In order to comply with the intent of Ontario Water Resources Act Regulation 903 amended to O. Reg. 128/03, the boreholes were sealed with reverse augering techniques for the full depth and, where appropriate, the surface was sealed with a bentonite plug.

The ground surface elevations at the borehole locations were measured based on a temporary benchmark described as the top of a bolt located along the north wood curb, at the centerline of the creek/bridge. This temporary benchmark was assigned an elevation of 100.1 m by the Client, D.M. Wills.

3 Subsurface Conditions

Soil conditions are confirmed at the boring locations only and may vary between borings. The boundaries between stratums indicated on the borehole logs are inferred from non-continuous sampling, results of in-situ tests (i.e. SPT, etc.), observations during the drilling operations, and/or the response of the drilling equipment. These boundaries are approximations only and should not be regarded as exact planes of geological change as the actual transition may be gradual from one soil type to another. The description of compactness of the granular subsoils, in part, was based on the results of the SPT, DCPT, and/or the response of the drilling equipment. The consistency of very fine cohesive subsoils, if encountered, was based on in-situ vane tests. Refusal is defined as the point at which the augers can no longer be practically advanced with the equipment used in this investigation. Refusal to further advance of the augers, DCPT and/or SPT may have been due to the presence of very dense soils, cobbles/boulders in the underlying soils, or possibly bedrock. Defining the nature of auger refusal with diamond drilling operations was undertaken at one location.

Detailed descriptions of the subsurface conditions revealed at the boreholes are shown on the enclosed Record of Borehole Logs in Appendix 2. The following is a brief description of revealed subsurface conditions at this site.

3.1 Subsurface Summary Description

3.1.1 Proposed Structure

Borehole Nos. 1 and 2 were put down in the area of the proposed bridge with BH No. 1 advanced to the west of the west abutment and BH No. 2 advanced to the east of the east abutment. The ground surface elevations at the boreholes were ±99.8 m.



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At surface at each of the boreholes, a deposit of brown sand fill, trace to some gravel, trace to some silt was penetrated. The natural moisture content measured on samples of this layer was in the order of 5 to 8% above elevation ±99.1 m and 17 to 23% below. SPT ‘N’ values ranged from 2 to 12. The compactness of this deposit was described as compact to very loose, but generally loose. A gradation (sieve) analysis was carried out on a sample of this deposit, the results of which indicated 7% gravel size particles, 82% sand size particles, and 11% silt and clay size particles (see Figure No. L-1, Appendix 3). This sample was found to meet OPSS Form 1010 requirements for Select Subgrade Material and exhibit a low susceptibility to frost heaving. The fill was encountered to depths of 1.4 and 2.0 m below grade at BH Nos. 1 and 2, respectively (elevations 98.4 and 97.8 m respectively).

Underlying the sand fill at Borehole No. 1, an additional layer of fill was encountered. This fill layer was described as black sand, and included wood pieces. A natural moisture content measured on a sample of this deposit was in the order of 43%. Based on a SPT ‘N’ value of 2 in this deposit, the compactness of this layer was described as very loose. This fill layer was encountered to a depth of 2.2 m below grade (elevation 97.6).

Underlying the sand fills at both boreholes, an organic stratum of dark brown amorphous peat with fibers and rootlets was penetrated. The natural moisture content measured on samples of this layer was in the order of 194 to 532%. SPT ‘N’ values ranged from 0 (weight of hammer) to 4. In-situ vane shear strengths returned values in the order of 40 kPa. The peat was encountered to depths of 3.5 and 3.2 m below grade at BH Nos. 1 and 2, respectively (elevations 96.3 and 96.6 m respectively).

Underlying the peat, a deposit of grey fine silt and sand was penetrated. The natural moisture content measured on samples of this layer was in the order of 17 to 33%. SPT ‘N’ values ranged from 9 to 19. The compactness of this deposit was described as compact. A gradation (sieve) analysis was carried out on a sample of this deposit, the results of which indicated 0% gravel size particles, 44% sand size particles, and 56% silt and clay size particles (see Figure No. L-2, Appendix 3). These samples exhibit a low to moderate susceptibility to frost heaving. The silt and sand was encountered to depths of 5.5 and 4.4 m below grade at BH Nos. 1 and 2, respectively (elevations 94.3 m and 95.4 m respectively).

Underlying the silt and sand, a deposit of grey silt, some clay, trace sand was penetrated. The natural moisture content measured on samples of this layer was in the order of 21 to 23%. SPT ‘N’ values ranged from 8 to 23. The compactness of this deposit was described as loose to compact, generally compact. A gradation (hydrometer) analysis was carried out on a sample of this deposit, the results of which indicated 0% gravel size particles, 5% sand size particles, 84% silt size particles, and 11% clay size particles (see Figure No. L-3, Appendix 3). The silt was encountered to a depth of 6.6 m below grade at BH Nos. 1 and 2 (elevations 93.2 m), where sampling in the boreholes was terminated.


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A DCPT was driven from the bottom of each borehole. DCPT refusal (100 blows/300 mm penetration) was encountered at BH Nos. 1 and 2 at depths of 10.3 and 10.5 m below grade respectively (elevations 89.5 and 89.3 m respectively).

A summary of the borehole ground surface elevations and auger refusal elevations is included in Table 1 below.

Table 1 Borehole Refusal

BOREHOLE ID SURFACE ELEVATIONS

(m) DCPT REFUSAL DEPTH

(m) DCPT REFUSAL ELEVATION (m)

BH 1 99.8 10.3 89.5

BH 2 99.8 10.5 89.3

3.2 Groundwater Data

Groundwater and cave-in levels in the open boreholes were measured, where possible, during the advance of the individual borings and upon completion. It is noted that there may have been insufficient time for the groundwater levels to stabilize in the boreholes prior to measuring. These levels are recorded on the individual Record of Borehole Log Sheets (Appendix B).

Groundwater levels will fluctuate seasonally and/or yearly. As such, the groundwater level should be established in advance of the construction operations (i.e. at time of tender or following award, prior to starting site work) such that adequate groundwater control plans can be developed.

At the time of the site visit, the water level in the creek was measured at elevation 98.8 m and the bottom of the creek was measured at elevation 98.4 m at the north side of the bridge and 98.0 m at the south side.

3.2.1 Area of Proposed Structure

Table 2 Groundwater Levels at Structure Location

BORING ID SURFACE ELEVATIONS

(m) GROUNDWATER DEPTH

(m) GROUNDWATER ELEVATION (m)

BH 1 99.8 0.9 98.9 (Cave-in 95.2 m)

BH 2 99.8 1.9 97.9 (Cave–in 96.2 m)



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4 Discussion and Recommendations

It is understood that it is proposed to replace the existing Axe Lake Road River Bridge located on Axe Lake Road near Sprucedale, Ontario. Work at the site includes removal of the existing bridge structure including timber crib abutments and replacement with modular steel girder bridge on new foundation.

The single lane bridge is a steel girder structure supported on timber cribs at the abutments. The bridge has a wood deck. See Photo Essay Appendix 4.

In general, the overburden at the site consists of surficial deposits of mostly granular fill overlying peat, overlying compact silts of varying sand content. The water table was encountered at a similar elevation as the water level in the creek.

4.1 Frost Protection

The estimated depth of frost penetration for the area is about 1.8 m for exposed surfaces such as roads. As such, foundation elements, which are subject to frost penetration, must be supplied with a minimum of 1.8 m of earth cover (both horizontally and vertically) for frost protection. If a sufficient depth of earth cover cannot be provided for frost protection, equivalent Expanded Extruded Polystyrene insulation (EEP) may be used in conjunction with available soils cover to provide frost protection. If EEP is used for frost protection, precautions must be taken to protect the insulation from contact with hydrocarbons, solvents, or other destructive products. The buoyancy of the product must be considered in the design unless sufficient cover weight is provided to counter the effects, which may limit the use of EEP to above the high water level.

4.2 Foundation Recommendations

As noted, it is understood that the existing bridge appears to be supported on wood cribs at the abutment locations. This bridge and its founding elements will be removed and replaced.

While shallow foundations could be considered for supporting the new bridge, there are challenges associated with shallow foundations at this site, including:

±1.2 to 1.3 m of compressible peat,

High groundwater table,

Potential settlement of foundation elements,

Scour protection, and

Construction/excavation considerations.

The presence of some 1.2 to 1.3 m of peat precludes the use of shallow foundations without removal of the peat due to the potential for excessive settlement. While crib type foundations


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are more tolerant of total and differential settlement, the potential settlement associated with 1.2 to 1.3 m of peat would be well beyond those limits.

The peat is submerged, the underside of which is some 1.3 to 2.6 m below the groundwater table. To remove the peat and replace with engineered fill would require the installation of a cofferdam around the foundation area combined with dewatering operations. The cofferdam, likely interlocking sheet piles, would have to be driven to sufficient depth below the excavation base (5+ m) to prevent piping/boiling at the excavation base. The groundwater would have to be drawn down by some 3 m (i.e. to ±1 m below the base of the excavation) to allow the peat to be removed and to maintain a stable excavation base during backfilling and foundation construction.

Alternatively, the new bridge structure could be founded on reinforced concrete abutments that are supported on deep foundations. Considering the subsurface conditions (fill overlying peat overlying silts), conventional end bearing piles (steel H piles or pipe pipes), driven to refusal in the underlying dense soils at depth or possibly on bedrock, are considered the optimal deep foundation system. Micropiles would also be suitable but are likely more expensive and therefore have not been considered. While helical piles could be considered, due to the nature of the subgrade soils, it is possible that helical piles may not develop sufficient resistance in torque until significant depth, or possibly not at all if refusal is encountered first.

4.2.1 Scour Considerations

One of the primary design criteria for the bridge foundation elements is that they must be protected from the effects of scour. This may be accomplished by founding the footings below the anticipated scour depth and/or by protecting the footings from the effects of scour (i.e. rock protection, concrete revetment, sheet pile walls, etc.). Shallow foundations are more susceptible to scour than abutments and/or piers supported on deep foundations. Scour depth and protection required shall be as per the Canadian Highway Bridge Design Code (CHBDC). A piled foundation does not provide complete protection against scour effects/failure, but piles can withstand much greater depths of scour than strip footings. Typically with a piled foundation, scour protection is provided to prevent washout of the approach from behind the footings/abutment.

Shallow foundations can be used provided they are protected from scour. If cribbing is used, the bottom round of the cribbing should either be level with or below the lowest point in the stream bed, or the face of the abutment should be established a minimum of 500 mm back from the top of a 2H:1V slope extending down to the channel bottom.

For foundation elements supported on deep foundations, the foundation must be founded at a minimum 1 m below the ultimate stream bed or provided with scour protection.

Scour protection can be provided through the use of rip/rap or rock protection mats or permanent sheet piles. The use of sheet piles can be combined with a dewatering program that allows the foundations to be constructed below the water level. Sheet piles to be used for



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scour protection should extend around the ends of the abutment footings and into the permanent shoreline a minimum of 1.5 m.

Besides, or combined with, foundation depth, scour protection can be supplied through the placement of OPSS 1004 R-50 Rip-Rap or Rock Protection (with 50% by volume greater than 300 mm in diameter), 500 mm (minimum) thick and extend from 400 mm above the high water level down 400 mm below the normal water level. The scour protection should extend to a minimum of 3 m beyond the abutments upstream and downstream.

In consideration of the granular nature of the existing approach fills, it would be prudent to place the rip-rap/rock protection on a non-woven Class II geotextile with FOS 105 – 210 um.

4.2.2 Shallow Foundation Recommendations

Consideration could be given to establishing abutments on shallow foundations, provided the peat is removed and sufficient scour protection can be provided.

Organics and other deleterious materials must be removed from the area of influence of the foundations down to native subgrade. As noted, this will require the use of a cofferdam combined with dewatering. Provided the natural subgrade is properly protected/prepared, engineered fill can then be used to bring the subgrade up to the underside of cribs or other type of shallow foundation.

All founding subgrades must be inspected and approved by a qualified member of this firm prior to forming footings or placing engineered fill. The contractor should minimize worker traffic within the foundation formwork and the excavation must be maintained in an unwatered condition during foundation construction. If the founding subgrade is excessively disturbed during excavation and foundation construction operations, it may have to be subexcavated and replaced with engineered fill or non-shrink fill.

Engineered fill shall be placed within the area of influence of the foundation and consist of OPSS Form 1010 Granular B Type 2 placed in lifts and compacted to 100% SPDD. The area of influence below the individual foundation unit, in cross section, is described as a trapezoid that extends outwards, horizontally from the edges of the foundation, a minimum of 300 mm and then downwards on a 2V:1H outward angle to undisturbed native competent soil.

For footings established at the depth below finished grade required for frost protection, provided with sufficient scour protection, and supported on properly constructed engineered fill (i.e. 100% SPDD) supported on undisturbed natural soils:

Factored Geotechnical Resistance at ULS: 300 kPa Geotechnical Reaction at SLS of 25 mm total settlement: 150 kPa net bearing

pressure increase

Based on the above noted design bearing pressures, and assuming proper subgrade preparation, settlements of the foundation units on soil for the structure will be well within the generally accepted tolerance range for this type of structure (i.e. 25 mm total and 19 mm differential).


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4.2.3 Deep Foundation Recommendations

4.2.3.1 End Bearing Piles

End bearing piles, including H piles or steel pipe piles can be considered for support of the bridge abutments. In order to obtain full axial capacity of a conventional end bearing pile foundation system, the piles should be driven to practical refusal into the underlying dense to very dense overburden overlying bedrock, or possibly seated on bedrock. As noted, DCPT refusal was encountered at elevations 89.5 and 89.3 m. Driven piles tend to advance 3 to 5 m beyond the DCPT refusal unless bedrock is encountered first.

Piles should be a minimum of 10 times the pile diameter in length, from the bearing tip to the underside of the pile cap, in order to provide sufficient lateral support. As such, end bearing piles will be suitable at the approaches. It must be noted that the bedrock surface can vary greatly in elevation over short horizontal distances. Sloping bedrock can result in difficulties setting the piles. If end bearing piles are used, at a minimum, piles should be fitted with rock points.

For base design, a 310x110 steel H-Pile has been considered. For preliminary design a factored geotechnical resistance at ULS of 850 kN per pile can be used for preliminary design of piles driven to refusal.

The piles will have to be driven to a “set criteria” as established for this design load by a dynamic pile driving formula (i.e. Hiley Formula, etc.) and proven through dynamic load testing (PDA) in the field. If the piles are installed through vibratory methods, a full axial compression load test will as per ASTM 1143 be required on a representative number of piles. Refusal depths will vary.

The contractor should be encouraged to submit alternatives together with material and driving methods including “set” criteria (alternative and base design) which in their opinion will satisfy the objectives of safe design load. The driving energy and final “set” criteria is normally developed by the piling contractor to satisfy specified loads as shown on the drawings. The piling contractor must carry out a sufficient number of load tests (per pile type) to prove the design capacity. A dynamic pile capacity analyzer (PDA) can be used for this purpose for driven piles. If piles are installed by other methods (i.e. vibratory) or a different type of deep foundation is selected, full scale load testing in accordance with ASTM D1143 must be undertaken. The price of the load testing must be included in the contractors bid. The deep foundation installation must be monitored full time by a qualified engineering inspection firm.

The soil characteristics governing pile capacity and settlement differ from the original soil characteristics of the deposit prior to driving. For example, the driving of piles in dense saturated fine sands and non-cohesive silts may cause the soils to dilate, producing a negative pore pressure and a temporary higher strength that “relaxes” once the pore pressure dissipates. Alternatively, the driving of the pile may locally cause “liquefaction”, even in dense sands, which causes a reduced resistance to pile penetration during driving, however the subsoil strength returns once the pore pressure dissipates. This fact, in addition to the heterogeneous nature of the deposits, makes the predication of pile behavior by analytical



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methods extremely difficult. As noted, the “set” criteria and pile capacity must be proven in the field through dynamic pile capacity analysis or full load tests and, due to the effect of driving piles on the subsoils, a representative number (i.e. 10%) of driven piles must be “restruck” once equilibrium conditions in the soil have been developed to estimate soil set up characteristics (i.e. minimum of one day post driving).

4.2.3.2 Helical Piles

As noted, the loose/compact silt overburden may preclude the use of helical piles. Helical piles are a proprietary system and there are different configurations that may be used to meet the founding and loading conditions. In general, helical “screw” piles consist of a steel pipe with helical plates that are installed through rotation into the ground. The pile capacity varies with the shaft diameter and helix dimensions and spacing. The soil conditions should be provided to the designer to confirm that their proprietary system would be suitable at this site.

During installation of the helical piles, the torque of the installation must be monitored to ensure that the minimum torque (as provided by the helical pile designer) is achieved.

The design of the helical pile system must be carried out by a Professional Engineer registered in the Province of Ontario, who shall also specify the load testing requirements.

4.2.4 Lateral Earth Pressure

The proposed abutments will retain the soil from the roadway approaches and should therefore be designed as retaining walls. Backfill behind retaining walls should be an imported well-graded free draining material (i.e. Granular B Type I) and be compacted to a minimum of 98% SPDD below settlement sensitive areas. Compaction efforts within 1.8 m of the cribbing/wall should be carried out with small hand operated compaction equipment and should not commence until the wall is properly supported or braced.

Lateral earth pressures should be computed in accordance with the Canadian Highway Bridge Design Code (CHBDC). The design parameters for the native soils and possible backfill materials are as follows:

PARAMETER GRANULAR A

GRANULAR B TYPE II

GRANULAR B TYPE I

EXISTING FILL/SSM

NATIVE SILT AND SAND

Unit Weight (kN/m3) 22.8 23.2 21.2 20 18.0Effective Angle of Internal Friction

34° 34° 31° 30° 29°

Coefficient of Active Earth Pressure (Ka)

0.28 0.28 0.32 0.33 0.35

Coefficient of Passive Earth Pressure (Kp)

3.54 3.54 3.12 3.00 2.88

Coefficient of Earth Pressure at Rest (Ko)

0.44 0.44 0.48 0.50 0.52

For most bridge abutments and piers, deflection can occur, as such the “active” condition (Ka) applies


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4.2.5 Earthquake Parameters

Considering the variable overburden conditions and the known geotechnical values:

CHBDC: o Soil Profile Type IV

NBCC 2010, Table 4.1.8.4A, Site Classification for Seismic Site Response: o Site Class E

4.3 Excavation, Dewatering, and Backfill

Based on the Occupational Health and Safety Act Regulations for Construction Projects, the soil at this site is classified as Type 4. All excavations greater than 1.2 m in depth must be sloped or shored in accordance with the Occupational Health and Safety Act Regulations for Construction Projects. Short-term (i.e. day) open excavations will be stable above the groundwater table at a temporary angle of 1H:1V, however excavations established at this slope must not be left unattended at any time. Below the prevailing groundwater table, the slopes of open excavations will have to be flattened to 2H:1V or possibly shallower depending upon the method of dewatering employed, or possibly sheeted.

Excavations or other operations carried out in the waterbody, or in close proximity to the waterbody, must be carried out in accordance with governing safety requirements and environmental regulations, to ensure there are no releases into the waterbody.

As noted, sheeting and a dewatering system will likely be required to construct the foundations. A dewatered subgrade condition must be maintained at all times during foundation construction until backfilling is a sufficient height above the prevailing water table (i.e. at a minimum 1 m). During these investigations, the groundwater was encountered at elevations of ±97.9 to 98.9 m. Groundwater levels will fluctuate both seasonally and yearly. The Contractor must undertake to establish the groundwater level in advance of the construction operations such that adequate groundwater control plans can be developed.

It must be emphasized that, when wet, silty soils (such as encountered at this site) can be easily disturbed through excavation operations, foot traffic, etc. and such disturbed soils can lose a significant amount of the native bearing. In addition, the placement of a working pad of engineered fill overtop of the fine grained soil is strongly recommended.

Ultimately, the method of dewatering will be the choice of the contractor. The importance and benefits of maintaining a dry stable subgrade during excavation and foundation construction cannot be stressed enough. Failure by the contractor to adequately control the groundwater, and/or rainwater, surficial runoff, etc., can result in disturbance to the founding subgrades, which can result in having to carry out corrective measures (i.e. additional excavation, time delays, etc.) to improve the subgrade. Corrective measures required to improve subgrades where groundwater is not adequately controlled will be at the Contractors cost. As part of the Contractors proposed methodology of construction, the Contractor should be requested to



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submit a dewatering plan prior to commencement of the project that details how they will control groundwater. The plan should include all aspects from methodology (i.e. sump holes and pumps, drainage ditches, vacuum well points), to construction of system (sump hole details, placement, etc.), to operation of system, etc.

The EPA requires a person who is engaging in the prescribed water taking activities set out in O. Reg. 63/16, that meet the criteria set out in that regulation, to register those activities in the EASR.

When approaching the founding soil subgrade surface, the excavating Contractor should use equipment that will not leave deep gouges in the bearing surface.

The sand fill was found to meet OPSS for Select Subgrade Material and can be reused where SSM is called for.

Any granular material to be used as engineered fill on this site must be tested and approved by this office prior to delivery to the site. It should be noted that engineered fill(s) should be placed in lifts of thickness less than the effective compaction depth of the equipment used to carry out the compaction operations (i.e. if using a heavy diesel Wacker lifts should be a maximum of 300 mm thick, etc.).

All granular backfill must be free of frost, ice, and snow, and at an appropriate moisture content and temperature to allow compaction. Once a lift of engineered fill is placed, compacted, and accepted, it is considered acceptable to backfill overtop of this lift if the lift is unfrozen or if there is minimal frost within the surface of the lift. If the surface of a granular fill lift is frozen, the Contractor shall, in conjunction with an Englobe representative, confirm depth of frost prior to backfilling. It is noted that frost penetration can be reduced through the use of insulated tarps, with or without heat source (depending upon ambient temperatures), and by ensuring backfilling operations are continuous.


12 Our Ref. : P-0016727-0-00-100-01

5 Limitations

The design recommendations given in this geotechnical report are applicable only to the project described in the text and only if constructed substantially in accordance with details of alignment and elevations stated in the report. Since all details of the design may not be known, in our analysis certain assumptions had to be made. The actual conditions may however, vary from those assumed, in which case changes and modifications may be required to our geotechnical recommendations. We recommend, therefore, that we be retained and provided the opportunity during the design stage to review the design drawings, site survey information, proposed elevations, etc. to verify that they are consistent with our recommendations or the assumptions made in our analysis. It is further recommended that we be retained to review the final design drawings and specifications relative to the geotechnical recommendations. If, during construction, conditions in the field vary from those assumed at the design stage, an engineer from this office must be notified immediately.

Proper subgrade preparation, groundwater control, compaction, etc. are all critical aspects of the bearing capacity of native soils. It must be noted that different aspects of the geotechnical design are based on the assumption that Englobe will be retained during site preparation and construction of the proposed works to ensure that both the geotechnical site characteristics and the construction operations/techniques are consistent with our recommendations. Should Englobe not be involved during the full construction phase, our liability is strictly limited to the factual information contained herein only.

The comments in this report are intended solely for the guidance of the design team and address the geotechnical conditions only. The number of boreholes required to determine the localized conditions between boreholes directly affecting construction costs, equipment, scheduling, etc. would in fact be greater than what has been carried out for design purposes. Inclusion of the factual information (Sections 1 to 3 inclusive) in the tender documents is furnished merely for the general information of bidders and is not in any way warranted or guaranteed by or on behalf of the owner or the owner's consultants and its subconsultants or the consultants' or subconsultants' employees, and neither the owner nor its consultants or its employees shall be liable for any representations negligent or otherwise contained in the documents. Therefore, contractors bidding on this project or undertaking this work should make their own interpretations of the factual borehole results and carry out further work as they deem necessary to assess the scope of the project.

Section 4 of this report is intended solely for the use of the client and the design team. If this section is provided to the Contractor, it is solely to provide an understanding of the geotechnical aspects of the site, and alternatives presented are not to be considered potential substitutes of the final design. If there is a discrepancy between this report and the tender documents and/or construction drawings, the latter shall govern and the discrepancy must be immediately brought to the attention of the design team.



Our Ref. : P-0016727-0-00-100-01

Appendix 1 Drawings Drawing No. 1 Key Plan

Drawing No. 2 Borehole Location Plan

D.M. Wills

Man.Project Otp

Electronic ref.

Rev.Project Phase

JRB P-0016727 -GE--- -- ---- 00--

Geotechnical Investigation

Axe Lake Road Bridge

Township of McMurrich-Monteith, Ontario

Key Plan (Macro)

Not To Scale

Geotechnical

Discipline:

Page setup:

Scale:

Date:

Prepare by:

Draw by:

Paper size:

Verify by:

Approval by:

Register no.:

Drawing no:

DM

DM

Macro

RG

JRB

----------

1a

2018/08/29

8.50 X 11.00 in.

2–120 Progress Court

North Bay, Ontario, P1A 0C2

705-476-2550

C:\U

sers\grasry\D

esktop\T

hings to be filed\F

IN

AL - A

xe Lake R

oad\A

ppendix N

o. 1\W

orking\P

-0016727 - B

orehole Location P

lan (F

inal).dw

g

No. DateVersion Appr.By VerifVersion

01 FINAL DM RG JRB2018/12/06

CONFIDENTIALITY STATEMENT. This document, protected by law, is the property of Englobe

and is for the sole use of the intended purpose. Any distribution or modification, partial or total,

is strictly prohibited without prior written approval from Englobe Corp.

SITE

D.M. Wills

Man.Project Otp

Electronic ref.

Rev.Project Phase

JRB P-0016727 -GE--- -- ---- 00--




Key Plan (Micro)

Not To Scale

Geotechnical

Discipline:

Page setup:

Scale:

Date:

Prepare by:

Draw by:

Paper size:

Verify by:

Approval by:

Register no.:

Drawing no:

DM

DM

Micro

RG

JRB

----------

1b

2018/08/29

8.50 X 11.00 in.



705-476-2550

C:\U

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esktop\T

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IN

AL - A

xe Lake R

oad\A

ppendix N

o. 1\W

orking\P

-0016727 - B

orehole Location P

lan (F

inal).dw

g






SITE

BH-2

GE: 99.8m

RE: 89.3 m

BH-1

GE: 99.8 m

RE: 89.5 m

D.M. Wills

Man.Project Otp

Electronic ref.

Rev.Project Phase

JRB P-0016727 -GE--- -- ---- 00--




Borehole Location Plan

Not To Scale

Geotechnical

Discipline:

Page setup:

Scale:

Date:

Prepare by:

Draw by:

Paper size:

Verify by:

Approval by:

Register no.:

Drawing no:

DM

DM

BH Plan

RG

JRB

----------

2

2018/08/29

8.50 X 11.00 in.



705-476-2550

C:\U

sers\grasry\D

esktop\T

hings to be filed\F

IN

AL - A

xe Lake R

oad\A

ppendix N

o. 1\W

orking\P

-0016727 - B

orehole Location P

lan (F

inal).dw

g








Our Ref. : P-0016727-0-00-100-01

Appendix 2 Subsurface Data Enclosure No. 1 List of Abbreviations and Symbols

Enclosure Nos. 2 and 3 Record of Borehole Sheets

Enclosure No. 1 Page 1 of 2

Englobe Corp.

LIST OF ABBREVIATIONS & DESCRIPTION OF TERMS

The abbreviations and terms, used to describe retrieved samples and commonly employed on the borehole logs, on

the figures and in the report are as follows:

1. ABBREVIATIONS AS Auger Sample CS Chunk Sample DS Denison type sample FS Foil Sample NFP No Further Progress PH Sampler advanced by hydraulic pressure PM Sampler advanced by manual pressure RC Rock core with size & percentage of recovery SS Split Spoon ST Slotted Tube TO Thin-walled, open TP Thin-walled, piston WS Wash Sample

2. PENETRATION RESISTANCE/"N" Dynamic Cone Penetration Test (DCPT): A continuous profile showing the number of blows for each 300 mm of penetration of a 50 mm diameter 60° cone attached to AW rod driven by a 63 kg hammer falling 760 mm.

Plotted as Standard Penetration Test (SPT) or "N" Values The number of blows of a 63 kg hammer falling 760 mm required to advance a 50 mm O.D. drive open sampler 300 mm.

3. SOIL DESCRIPTION a) Cohesionless Soils:

"N" (blows/0.3 m) Compactness Condition

0 to 4 very loose 4 to 10 loose

10 to 30 compact 30 to 50 dense over 50 very dense

3. SOIL DESCRIPTION (Cont'd) b) Cohesive Soils:

Undrained Shear Strength (kPa)

Consistency

Less than 12 very soft 12 to 25 soft 25 to 50 firm

50 to 100 stiff 100 to 200 very stiff over 200 hard

c) Method of Determination of Undrained Shear Strength of Cohesive Soils: + 3.2 - Field Vane test in borehole. The number denotes the sensitivity to remoulding. D - Laboratory Vane Test ¨ - Compression test in laboratory

For a saturated cohesive soil the undrained shear strength is taken as one-half of the undrained compressive strength.

4. TERMINOLOGY Terminology used for describing soil strata is based on the proportion of individual particle sizes present in the samples (please note that, with the exception of those samples subject to a grain-size analysis, all samples were classified visually and the accuracy of visual examination is not sufficient to determine exact grain sizing):

Trace, or occasional Less than 10% Some 10 to 20% With 20 to 30% Adjective (i.e. silty or sandy) 30 to 40% And (i.e. sand and gravel) 40 to 60%

5. LABORATORY TESTS P Standard Proctor Test A Atterberg Limit Test GS Grain Size Analysis H Hydrometer Analysis C Consolidation

Enclosure No. 1 Page 2 of 2

Englobe Corp.

SAMPLE DESCRIPTION NOTES:

1. FILL: The term fill is used to designate all man-made deposits of natural soil and/or waste materials. The reader is cautioned that fill materials can be very heterogeneous in nature and variable in depth, density and degree of compaction. Fill materials can be expected to contain organics, waste materials, construction materials, shot rock, rip-rap, and/or larger obstructions such as boulders, concrete foundations, slabs, abandoned tanks, etc.; none of which may have been encountered in the borehole. The description of the material penetrated in the borehole therefore may not be applicable as a general description of the fill material on the site as boreholes cannot accurately define the nature of fill material. During the boring and sampling process, retrieved samples may have certain characteristics that identify them as ‘fill’. Fill materials (or possible fill materials) will be designated on the Borehole Logs. If fill material is identified on the site, it is highly recommended that testpits be put down to delineate the nature of the fill material. However, even through the use of testpits defining the true nature and composition of the fill material cannot be guaranteed. Fill deposits often contain pockets or seams of organics, organically contaminated soils or other deleterious material that can cause settlement or result in the production of methane gas. It should be noted that the origins and history of fill material is frequently very vague or non-existent. Often fill material may be contaminated beyond environmental guidelines and the material will have to be disposed of at a designated site (i.e. registered landfill). Unless requested or stated otherwise in this report, fill material on this site has not been tested for contaminants however, environmental testing of the fill material can be carried out at your request. Detection of underground storage tanks cannot be determined with conventional geotechnical procedures.

2. TILL: The term till indicates a material that is an unstratified, glacial deposit, heterogeneous in nature and, as such, may consist of mixtures and pockets of clay, silt, sand, gravel, cobbles and/or boulders. These heterogeneous deposits originate from a geological process associated with glaciation. It must be noted that due to the highly heterogeneous nature of till deposits, the description of the deposit on the borehole log may only be applicable to a very limited area and therefore, caution must be exercised when dealing with a till deposit. When excavating in till, contractors may encounter cobbles/boulders or possibly bedrock even if they are not indicated on the borehole logs. It must be appreciated that conventional geotechnical sampling equipment does not identify the nature or size of any obstruction.

3. BEDROCK: Auger refusal may be due to the presence of bedrock, but possibly could also be due to the presence of very dense underlying deposits, boulders or other large obstructions. Auger refusal is defined as the point at which an auger can no longer be practically advanced. It must be appreciated that conventional geotechnical sampling equipment does not differentiate between nature and size of obstructions that prevent further penetration of the boring below grade. Bedrock indicated on the borehole logs will be labeled ‘possibly’ or ‘probable’ etc. based on the response of the boring and sampling equipment, surrounding topography, etc. Bedrock can be proven at individual borehole locations, at your request, by diamond core drilling operations or, possibly, by testpits. It must also be appreciated that bedrock surfaces can be, and most times are, very erratic in nature (i.e. sheer drops, isolated rock knobs, etc.) and caution must be used when interpreting subsurface conditions between boreholes. A bedrock profile can be more accurately estimated, at the clients’ request, through a series of closely positioned unsampled auger probes combined with core drilling.

4. GROUNDWATER: Although the groundwater table may have been encountered during this investigation and the elevation noted in the report and/or on the record of boreholes, it must be appreciated that the elevation of the groundwater table will fluctuate based upon seasonal conditions, localized changes, erratic changes in the underlying soil profile between boreholes, underlying soil layers with highly variable permeabilities, etc. These conditions may affect the design and type and nature of dewatering procedures. Cave-in levels recorded in borings give a general indication of the groundwater level in cohesionless soils however, it must be noted that cave-in levels may also be due to the relative density of the deposit, drilling operations etc.

FILL - sand, trace gravel, trace tosome siltbrown(loose)

layer of black sand

FILL - sand, with wood pieces

black

(very loose)

PEAT, fibrous

50 mm medium-fine sand

dark brown

(very loose)

SILT and SAND - trace clay

grey

(compact)

SILT - trace sand, some clay

grey

(loose/compact)

End of Sampling

DCPT RefusalEnd of Borehole

1

2

3

4A4B

5A

5B

6

7

8

(11)

(56)

11

98.4

97.6

96.3

94.3

93.2

89.5

82

44

5

SS

SS

SS

SS

SS

SS

SS

SS 84

6

6

2

WH

2

17

9

23

1.4

2.2

3.5

5.5

6.6

10.3

7

0

0

8/23/18 9:33:00 AM

3

0.9

Water Depth (m):

1)

8/23/18 12:45:00 PM

3

8/23/18 11:20:00 AM

COMMENTS ,

4.61.3

STRAIN AT FAILURE3%

Cave In (m)

1.4

WATER LEVEL RECORDS

12)

The stratification lines represent approximate boundaries. The transition may be gradual. 1.23)

Date (dd/mm/yy)/TimeNumbers on right refer toSensitivityNumbers on left refer tovalues greater than 100 kPa

ENCLOSURE NO.:

20 40 60

P-0016727

August 23, 2018August 23, 2018

TIME(Completed)

20 40 60 80 100

kN/m3

DYNAMIC CONE PENETRATIONRESISTANCE PLOT

LOCATION

BOREHOLE TYPE

REFERENCE

SA

COMPILED BY

CLIENT

NU

MB

ER

QUICK TRIAXIAL

CHECKED BY

LIQUIDLIMIT

WATER CONTENT (%)

wL

PLASTICLIMIT

(SI

DATE (Started)DATE (Completed)

ORIGINATED BY

TY

PE


METRIC

ELS

DM

w

GR

OU

ND

WA

TE

R

CO

ND

ITIO

NS

ELE

VA

TIO

N S

CA

LE

ELEV

D.M. Wills

DEPTH

See Borehole Location Plan; Appendix No. 1, Dwg No. 2

PROJECT

LAB VANE

REMARKS

&

GRAIN SIZE

DISTRIBUTION

(%)

2 (Pg. 1 of 1)

Ground Surface

9:20:00 AM

RECORD OF BOREHOLE NO. 1

UN

IT

WE

IGH

T

RG

99

98

97

96

95

94

93

92

91

90

CL)

0.0

"N"

VA

LUE

S

ST

RA

TA

PLO

T

DATUM

UNCONFINED

wPSHEAR STRENGTH kPa

99.8

Track Mounted CME 45 - Hollow Stem Augers

NATURALMOISTURECONTENT

SAMPLES

FIELD VANE

GR

SOIL PROFILE

20 40 60 80 100

DESCRIPTION(see Enclosure No. 1)

Englobe Corp.120 Progress Court, North Bay, On P1A 0C2 Phone: (705)476-2550 Fax: (705)476-8882 Email: [email protected]

TBM

ME

L-G

EO

P-0

0167

27 -

BO

RE

HO

LE L

OG

S, A

XE

LA

KE

RO

AD

(F

INA

L).G

PJ

ME

L-G

EO

.GD

T 1

2/6

/18

3

194.05

502.46

FILL - sand, some to trace gravel,trace silt

brown

(compact/very loose)

wood pieces encountered

wood pieces encountered

PEAT, fibrous

dark brown

(very loose)

SILT and SAND - trace claygrey(compact)

SILT - trace sand, some clay

with sand seams

grey

(loose/compact)

End of Sampling

DCPT RefusalEnd of Borehole

1

2

3A

3B3C

4

5A

5B

6

7

8

97.8

96.6

95.4

93.2

89.3

SS

SS

SS

SS

SS

SS

SS

SS

5

12

2

WH

19

19

8

23

2.0

3.2

4.4

6.6

10.5

8/23/18 11:30:00 AM

3

-

Water Depth (m):

1)

3

8/23/18 12:39:00 PM

COMMENTS ,

-1

STRAIN AT FAILURE3%

Cave In (m)

3.6

WATER LEVEL RECORDS

1.92)

The stratification lines represent approximate boundaries. The transition may be gradual. -3)

Date (dd/mm/yy)/TimeNumbers on right refer toSensitivityNumbers on left refer tovalues greater than 100 kPa

ENCLOSURE NO.:

20 40 60

P-0016727

August 23, 2018August 23, 2018

TIME(Completed)

20 40 60 80 100

kN/m3

DYNAMIC CONE PENETRATIONRESISTANCE PLOT

LOCATION

BOREHOLE TYPE

REFERENCE

SA

COMPILED BY

CLIENT

NU

MB

ER

QUICK TRIAXIAL

CHECKED BY

LIQUIDLIMIT

WATER CONTENT (%)

wL

PLASTICLIMIT

(SI

DATE (Started)DATE (Completed)

ORIGINATED BY

TY

PE


METRIC

ELS

DM

w

GR

OU

ND

WA

TE

R

CO

ND

ITIO

NS

ELE

VA

TIO

N S

CA

LE

ELEV

D.M. Wills

DEPTH

See Borehole Location Plan; Appendix No. 1, Dwg No. 2

PROJECT

LAB VANE

REMARKS

&

GRAIN SIZE

DISTRIBUTION

(%)

3 (Pg. 1 of 1)

Ground Surface

12:24:00 PM

RECORD OF BOREHOLE NO. 2

UN

IT

WE

IGH

T

RG

99

98

97

96

95

94

93

92

91

90

CL)

0.0

"N"

VA

LUE

S

ST

RA

TA

PLO

T

DATUM

UNCONFINED

wPSHEAR STRENGTH kPa

99.8

Track Mounted CME 45 - Hollow Stem Augers

NATURALMOISTURECONTENT

SAMPLES

FIELD VANE

GR

SOIL PROFILE

20 40 60 80 100

DESCRIPTION(see Enclosure No. 1)

Englobe Corp.120 Progress Court, North Bay, On P1A 0C2 Phone: (705)476-2550 Fax: (705)476-8882 Email: [email protected]

TBM

ME

L-G

EO

P-0

0167

27 -

BO

RE

HO

LE L

OG

S, A

XE

LA

KE

RO

AD

(F

INA

L).G

PJ

ME

L-G

EO

.GD

T 1

2/6

/18

3

289.3

532.44

279.54



Our Ref. : P-0016727-0-00-100-01

Appendix 3 Lab Data

Reference No.: P-0016727

Date: August, 2018

PROJECT: Axe Lake Road Bridge

LOCATION: Township of McMurrich-Monteith, Ontario

FILL

Englobe Corp. FIGURE L-1

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

PE

RC

EN

T P

AS

SIN

G (

%)

GRAIN SIZE IN MILLIMETERS

GRAIN SIZE ANALYSIS

BH No.: 1 Sa No.: 2 Depth: 0.8 - 1.2 m

GRAVEL

Coarse FineSILT & CLAY

SAND

Coarse Medium Fine


Date: August, 2018



SILT and SAND


0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

PE

RC

EN

T P

AS

SIN

G (

%)


GRAIN SIZE ANALYSIS

BH No.: 1 Sa No.: 6 Depth: 3.8 - 4.3 m

GRAVEL


SAND

Coarse Medium Fine


Date: August, 2018



SILT


0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

PE

RC

EN

T P

AS

SIN

G (

%)


GRAIN SIZE ANALYSIS

BH No.: 1 Sa No.: 8 Depth: 6.1 - 6.6 m

GRAVEL


SAND

Coarse Medium Fine



Our Ref. : P-0016727-0-00-100-01

Appendix 4 Photo Essay

Reference No.: P-0016727 August 2018

ENBLOBECORP.COM Enclosure No. 4 1 of 2

Axe Lake Road Bridge – Looking North Photo: 1

Creek - Looking South Photo: 2

Project: Axe Lake Road Bridge

Photos By: Englobe Date: August 2018

Reference No.: P-0016727 August 2018

ENBLOBECORP.COM Enclosure No. 4 2 of 2

Creek - Looking North Photo: 3

Underside of bridge Photo: 4

Project: Axe Lake Road Bridge

Photos By: Englobe Date: August 2018

www.englobecorp.com

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